! " # $ %&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^ _ ` a b c d e f g h i j k l m n o p q r s t u vwxyz{|}~ SafeReturn  on Windows and ! otherwise. A runtime version of #ifdef minw32_HOST_OS. Equivalent to os == "mingw32", but: more efficient; doesn't require typing an easily mistypeable string; actually asks about your OS not a library; doesn't bake in 32bit assumptions that are already false. </rant> isWindows == (os == "mingw32")Return  on Mac OS X and  otherwise.Safe  Safe2Show a number to a fixed number of decimal places. @showDP 4 pi == "3.1416" showDP 0 pi == "3" showDP 2 3 == "3.00";Specialised numeric conversion, type restricted version of .;Specialised numeric conversion, type restricted version of .;Specialised numeric conversion, type restricted version of .;Specialised numeric conversion, type restricted version of .0Safe %&/QRT-          Safe %Update the first component of a pair. #first succ (1,"test") == (2,"test")&Update the second component of a pair. 'second reverse (1,"test") == (1,"tset")iGiven two functions, apply one to the first component and one to the second. A specialised version of . +(succ *** reverse) (1,"test") == (2,"tset")aGiven two functions, apply both to a single argument to form a pair. A specialised version of . (succ &&& pred) 1 == (2,0) %Duplicate a single value into a pair. dupe 12 == (12, 12)!5Apply a single function to both components of a pair. both succ (1,2) == (2,3)" Extract the  of a triple.# Extract the  of a triple.$&Extract the final element of a triple.  !"#$ !" !"#$  !"#$  !"#$33SafeL1%aApply some operation repeatedly, producing an element of output and the remainder of the list. \xs -> repeatedly (splitAt 3) xs == chunksOf 3 xs \xs -> repeatedly word1 (trim xs) == words xs \xs -> repeatedly line1 xs == lines xs&Flipped version of #. for [1,2,3] (+1) == [2,3,4]'3Are two lists disjoint, with no elements in common. >disjoint [1,2,3] [4,5] == True disjoint [1,2,3] [4,1] == False(1Is there any element which occurs more than once. anySame [1,1,2] == True anySame [1,2,3] == False anySame (1:2:1:undefined) == True anySame [] == False \xs -> anySame xs == (length (nub xs) < length xs))Are all elements the same. allSame [1,1,2] == False allSame [1,1,1] == True allSame [1] == True allSame [] == True allSame (1:1:2:undefined) == False \xs -> allSame xs == (length (nub xs) <= 1)**Non-recursive transform over a list, like $. list 1 (\v _ -> v - 2) [5,6,7] == 3 list 1 (\v _ -> v - 2) [] == 1 \nil cons xs -> maybe nil (uncurry cons) (uncons xs) == list nil cons xs+If the list is empty returns %, otherwise returns the & and the '. unsnoc "test" == Just ("tes",'t') unsnoc "" == Nothing \xs -> unsnoc xs == if null xs then Nothing else Just (init xs, last xs),=Append an element to the start of a list, an alias for '(:)'. Ccons 't' "est" == "test" \x xs -> uncons (cons x xs) == Just (x,xs)-.Append an element to the end of a list, takes O(n) time. Csnoc "tes" 't' == "test" \xs x -> unsnoc (snoc xs x) == Just (xs,x).3Take a number of elements from the end of the list. takeEnd 3 "hello" == "llo" takeEnd 5 "bye" == "bye" takeEnd (-1) "bye" == "" \i xs -> takeEnd i xs `isSuffixOf` xs \i xs -> length (takeEnd i xs) == min (max 0 i) (length xs)/3Drop a number of elements from the end of the list. dropEnd 3 "hello" == "he" dropEnd 5 "bye" == "" dropEnd (-1) "bye" == "bye" \i xs -> dropEnd i xs `isPrefixOf` xs \i xs -> length (dropEnd i xs) == max 0 (length xs - max 0 i) \i -> take 3 (dropEnd 5 [i..]) == take 3 [i..]00 n xs> returns a split where the second element tries to contain n elements. splitAtEnd 3 "hello" == ("he","llo") splitAtEnd 3 "he" == ("", "he") \i xs -> uncurry (++) (splitAt i xs) == xs \i xs -> splitAtEnd i xs == (dropEnd i xs, takeEnd i xs)1 A merging of ( and ). 4concatUnzip [("a","AB"),("bc","C")] == ("abc","ABC")2 A merging of * and ). DconcatUnzip3 [("a","AB",""),("bc","C","123")] == ("abc","ABC","123")3 A version of + operating from the end. $takeWhileEnd even [2,3,4,6] == [4,6]4.Remove spaces from the start of a string, see 6.5,Remove spaces from the end of a string, see 6.6=Remove spaces from either side of a string. A combination of 5 and 4. trim " hello " == "hello" trimStart " hello " == "hello " trimEnd " hello " == " hello" \s -> trim s == trimEnd (trimStart s)7Convert a string to lower case. 9lower "This is A TEST" == "this is a test" lower "" == ""8Convert a string to upper case. 9upper "This is A TEST" == "THIS IS A TEST" upper "" == ""9Split the first word off a string. Useful for when starting to parse the beginning of a string, but you want to accurately perserve whitespace in the rest of the string. word1 "" == ("", "") word1 "keyword rest of string" == ("keyword","rest of string") word1 " keyword\n rest of string" == ("keyword","rest of string") \s -> fst (word1 s) == concat (take 1 $ words s) \s -> words (snd $ word1 s) == drop 1 (words s):"Split the first line off a string. line1 "" == ("", "") line1 "test" == ("test","") line1 "test\n" == ("test","") line1 "test\nrest" == ("test","rest") line1 "test\nrest\nmore" == ("test","rest\nmore"); A version of ,4 where the equality is done on some extracted value.< A version of -8 where the equality is done on some extracted value. nubOn f is equivalent to  nubBy ((==) . f):, but has the performance advantage of only evaluating f, once for each element in the input list.=A combination of , and /. groupSort [(1,'t'),(3,'t'),(2,'e'),(2,'s')] == [(1,"t"),(2,"es"),(3,"t")] \xs -> map fst (groupSort xs) == sort (nub (map fst xs)) \xs -> concatMap snd (groupSort xs) == map snd (sortOn fst xs)>A combination of , and /*, using a part of the value to compare on. UgroupSortOn length ["test","of","sized","item"] == [["of"],["test","item"],["sized"]]?A combination of , and /", using a predicate to compare on. dgroupSortBy (compare `on` length) ["test","of","sized","item"] == [["of"],["test","item"],["sized"]]@0Merge two lists which are assumed to be ordered. Rmerge "ace" "bd" == "abcde" \xs ys -> merge (sort xs) (sort ys) == sort (xs ++ ys)ALike @&, but with a custom ordering function.B]Replace a subsequence everywhere it occurs. The first argument must not be the empty list. replace "el" "_" "Hello Bella" == "H_lo B_la" replace "el" "e" "Hello" == "Helo" replace "" "e" "Hello" == undefined \xs ys -> not (null xs) ==> replace xs xs ys == ysCBreak, but from the end. breakEnd isLower "youRE" == ("you","RE") breakEnd isLower "youre" == ("youre","") breakEnd isLower "YOURE" == ("","YOURE") \f xs -> breakEnd (not . f) xs == spanEnd f xsDSpan, but from the end. spanEnd isUpper "youRE" == ("you","RE") spanEnd (not . isSpace) "x y z" == ("x y ","z") \f xs -> uncurry (++) (spanEnd f xs) == xs \f xs -> spanEnd f xs == swap (both reverse (span f (reverse xs)))E A variant of 0p with a custom test. In particular, adjacent separators are discarded, as are leading or trailing separators. ]wordsBy (== ':') "::xyz:abc::123::" == ["xyz","abc","123"] \s -> wordsBy isSpace s == words sF A variant of 1] with a custom test. In particular, if there is a trailing separator it will be discarded. linesBy (== ':') "::xyz:abc::123::" == ["","","xyz","abc","","123",""] \s -> linesBy (== '\n') s == lines s linesBy (== ';') "my;list;here;" == ["my","list","here"]GAFind the first element of a list for which the operation returns 22, along with the result of the operation. Like 3 but useful where the function also computes some expensive information that can be reused. Particular useful when the function is monadic, see  firstJustM. RfirstJust id [Nothing,Just 3] == Just 3 firstJust id [Nothing,Nothing] == NothingHEquivalent to drop 1., but likely to be faster and a single lexeme. Mdrop1 "" == "" drop1 "test" == "est" \xs -> drop 1 xs == drop1 xsI Version on 4 generalised to a 5 rather than just a list. JmconcatMap Sum [1,2,3] == Sum 6 \f xs -> mconcatMap f xs == concatMap f xsJFind the first instance of needle in haystack=. The first element of the returned tuple is the prefix of haystack before needle. is matched. The second is the remainder of haystack6, starting with the match. If you want the remainder without the patch, use P. breakOn "::" "a::b::c" == ("a", "::b::c") breakOn "/" "foobar" == ("foobar", "") \needle haystack -> let (prefix,match) = breakOn needle haystack in prefix ++ match == haystackK Similar to J+, but searches from the end of the string.9The first element of the returned tuple is the prefix of haystack( up to and including the last match of needle#. The second is the remainder of haystack, following the match. ,breakOnEnd "::" "a::b::c" == ("a::b::", "c")LBreak a list into pieces separated by the first list argument, consuming the delimiter. An empty delimiter is invalid, and will cause an error to be raised. <splitOn "\r\n" "a\r\nb\r\nd\r\ne" == ["a","b","d","e"] splitOn "aaa" "aaaXaaaXaaaXaaa" == ["","X","X","X",""] splitOn "x" "x" == ["",""] splitOn "x" "" == [""] \s x -> s /= "" ==> intercalate s (splitOn s x) == x \c x -> splitOn [c] x == split (==c) xMSplits a list into components delimited by separators, where the predicate returns True for a separator element. The resulting components do not contain the separators. Two adjacent separators result in an empty component in the output. split (== 'a') "aabbaca" == ["","","bb","c",""] split (== 'a') "" == [""] split (== ':') "::xyz:abc::123::" == ["","","xyz","abc","","123","",""] split (== ',') "my,list,here" == ["my","list","here"]N A version of ; but with different strictness properties. The function [ can be used on an infinite list and tests the property on each character. In contrast, No is strict in the spine of the list but only tests the trailing suffix. This version usually outperforms t if the list is short or the test is expensive. Note the tests below cover both the prime and non-prime variants. dropWhileEnd isSpace "ab cde " == "ab cde" dropWhileEnd' isSpace "ab cde " == "ab cde" last (dropWhileEnd even [undefined,3]) == undefined last (dropWhileEnd' even [undefined,3]) == 3 head (dropWhileEnd even (3:undefined)) == 3 head (dropWhileEnd' even (3:undefined)) == undefinedOVReturn the prefix of the second string if its suffix matches the entire first string. Examples: wstripSuffix "bar" "foobar" == Just "foo" stripSuffix "" "baz" == Just "baz" stripSuffix "foo" "quux" == NothingP@Return the the string before and after the search string, or %% if the search string is not present. Examples: TstripInfix "::" "a::b::c" == Just ("a", "b::c") stripInfix "/" "foobar" == NothingQ Similar to P+, but searches from the end of the string. 2stripInfixEnd "::" "a::b::c" == Just ("a::b", "c")RSplit a list into chunks of a given size. The last chunk may contain fewer than n elements. The chunk size must be positive. chunksOf 3 "my test" == ["my ","tes","t"] chunksOf 3 "mytest" == ["myt","est"] chunksOf 8 "" == [] chunksOf 0 "test" == undefinedS O(n log n). The S function removes duplicate elements from a list. In particular, it keeps only the first occurrence of each element. Unlike the standard -$ operator, this version requires an 67 instance and consequently runs asymptotically faster. onubOrd "this is a test" == "this ae" nubOrd (take 4 ("this" ++ undefined)) == "this" \xs -> nubOrd xs == nub xsT A version of S* which operates on a portion of the value. =nubOrdOn length ["a","test","of","this"] == ["a","test","of"]U A version of S with a custom predicate. LnubOrdBy (compare `on` length) ["a","test","of","this"] == ["a","test","of"]:789:;<%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTU=>?@AB#CDEFGHIJKLMNOPQ3RSTUVWX4)Y0Z1[\/]^_`a,bcdefghijklmnopqrstuvwxyz{|}~-*(+&'%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTU4786459:/.0CDN3OPQEFJKLMR*+,-HI=>?SUT<;')(%&G12B@A6789:;<%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTU=>?SafeXRead a  or throw an exception. G\x -> readVersion (showVersion x) == x readVersion "hello" == undefinedXXXXSafeY#Evaluates the value before calling .Z#Evaluates the value before calling .YZ YZYZYZSafe[The [( function extracts the element out of a + and throws an error if its argument is . Much like fromJust=, using this function in polished code is usually a bad idea. C\x -> fromLeft (Left x) == x \x -> fromLeft (Right x) == undefined\The \( function extracts the element out of a + and throws an error if its argument is . Much like fromJust=, using this function in polished code is usually a bad idea. E\x -> fromRight (Right x) == x \x -> fromRight (Left x) == undefined]Pull the value out of an / where both alternatives have the same type. ?\x -> fromEither (Left x ) == x \x -> fromEither (Right x) == x[\]  [\] [\][\] Safe^Perform some operation on 2, given the field inside the 2. GwhenJust Nothing print == return () whenJust (Just 1) print == print 1_Like ^$, but where the test can be monadic.`>The identity function which requires the inner argument to be ()7. Useful for functions with overloaded return types. \(x :: Maybe ()) -> unit x == xaMonadic generalisation of $.bMonadic generalisation of .c A version of  partition% that works with a monadic predicate. cpartitionM (Just . even) [1,2,3] == Just ([2], [1,3]) partitionM (const Nothing) [1,2,3] == Nothingd A version of 4% that works with a monadic predicate.eLike dI, but has its arguments flipped, so can be used instead of the common fmap concat $ forM pattern.f A version of  mconcatMap% that works with a monadic predicate.g A version of % that works with a monadic predicate.h1A looping operation, where the predicate returns # as a seed for the next loop or  to abort the loop.i+Keep running an operation until it becomes . As an example: IwhileM $ do sleep 0.1; notM $ doesFileExist "foo.txt" readFile "foo.txt" 8If you need some state persisted between each test, use h.jLike $, but where the test can be monadic.kLike $, but where the test can be monadic.lLike if$, but where the test can be monadic.mLike $, but where the test can be monadic.n The lazy C operator lifted to a monad. If the first argument evaluates to . the second argument will not be evaluated. uJust True ||^ undefined == Just True Just False ||^ Just True == Just True Just False ||^ Just False == Just Falseo The lazy C operator lifted to a monad. If the first argument evaluates to . the second argument will not be evaluated. vJust False &&^ undefined == Just False Just True &&^ Just True == Just True Just True &&^ Just False == Just Falsep A version of V; lifted to a monad. Retains the short-circuiting behaviour. anyM Just [False,True ,undefined] == Just True anyM Just [False,False,undefined] == undefined \(f :: Int -> Maybe Bool) xs -> anyM f xs == orM (map f xs)q A version of U; lifted to a monad. Retains the short-circuiting behaviour. allM Just [True,False,undefined] == Just False allM Just [True,True ,undefined] == undefined \(f :: Int -> Maybe Bool) xs -> anyM f xs == orM (map f xs)r A version of W; lifted to a monad. Retains the short-circuiting behaviour. orM [Just False,Just True ,undefined] == Just True orM [Just False,Just False,undefined] == undefined \xs -> Just (or xs) == orM (map Just xs)s A version of X; lifted to a monad. Retains the short-circuiting behaviour. andM [Just True,Just False,undefined] == Just False andM [Just True,Just True ,undefined] == undefined \xs -> Just (and xs) == andM (map Just xs)tLike find$, but where the test can be monadic. findM (Just . isUpper) "teST" == Just (Just 'S') findM (Just . isUpper) "test" == Just Nothing findM (Just . const True) ["x",undefined] == Just (Just "x")uLike tN, but also allows you to compute some additional information in the predicate.^_`abcdefghijklmnopqrstuB^_`abcdefghijklmnopqrstu^_`abhicdefgtujklmnorspq^_`abcdefghijklmnopqrstuSafevList the files and directories directly within a directory. Each result will be prefixed by the query directory, and the special directories . and ..9 will be ignored. Intended as a cleaned up version of . withTempDir $ \dir -> do writeFile (dir </> "test.txt") ""; (== [dir </> "test.txt"]) <$> listContents dir let touch = mapM_ $ \x -> createDirectoryIfMissing True (takeDirectory x) >> writeFile x "" let listTest op as bs = withTempDir $ \dir -> do touch $ map (dir </>) as; res <- op dir; return $ map (drop (length dir + 1)) res == bs listTest listContents ["bar.txt","foo/baz.txt","zoo"] ["bar.txt","foo","zoo"]wLike vy, but only returns the files in a directory, not other directories. Each file will be prefixed by the query directory. DlistTest listFiles ["bar.txt","foo/baz.txt","zoo"] ["bar.txt","zoo"]xLike w2, but goes recursively through all subdirectories. glistTest listFilesRecursive ["bar.txt","zoo","foo" </> "baz.txt"] ["bar.txt","zoo","foo" </> "baz.txt"]yLike x_, but with a predicate to decide where to recurse into. Typically directories starting with .V would be ignored. The initial argument directory will have the test applied to it. listTest (listFilesInside $ return . not . isPrefixOf "." . takeFileName) ["bar.txt","foo" </> "baz.txt",".foo" </> "baz2.txt", "zoo"] ["bar.txt","zoo","foo" </> "baz.txt"] listTest (listFilesInside $ const $ return False) ["bar.txt"] []z|Create a directory with permissions so that only the current user can view it. On Windows this function is equivalent to .vwxyz;     vwxyzzvwyxvwxyzSafeT{[Fully evaluate an input String. If the String contains embedded exceptions it will produce  <Exception>. (stringException "test" == return "test" stringException ("test" ++ undefined) == return "test<Exception>" stringException ("test" ++ undefined ++ "hello") == return "test<Exception>" stringException ['t','e','s','t',undefined] == return "test<Exception>"|@Show a value, but if the result contains exceptions, produce  <Exception> . Defined as { . show. Particularly useful for printing exceptions to users, remembering that exceptions can themselves contain undefined values.}+Ignore any exceptions thrown by the action. ?ignore (print 1) == print 1 ignore (fail "die") == return ()~Like error, but in the  monad. Note that while  in  raises an , this function raises an  exception. :try (errorIO "Hello") == return (Left (ErrorCall "Hello"))Retry an operation at most n times (n2 must be positive). If the operation fails the n+th time it will throw that final exception. Dretry 1 (print "x") == print "x" retry 3 (fail "die") == fail "die"Retry an operation at most n times (nh must be positive), while the exception value and type match a predicate. If the operation fails the n+th time it will throw that final exception. A version of  without the  context, restricted to , so catches all exceptions.Like  but for  Like  but for !Like  but for "Like  but for #Like  but for $pCatch an exception if the predicate passes, then call the handler with the original exception. As an example: ZreadFileExists x == catchBool isDoesNotExistError (readFile "myfile") (const $ return "") Like  but for !.Like  but for #.{|}~%f&'()*+,-./$#0"! 123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefg hijklmnopq{|}~|{~ }{|}~%Safe0.A type alias for seconds, which are stored as r.Sleep for a number of seconds. 3fmap (round . fst) (duration $ sleep 1) == return 1 A version of  that takes ) and never overflows the bounds of an sM. In addition, the bug that negative timeouts run for ever has been fixed. timeout (-3) (print 1) == return Nothing timeout 0.1 (print 1) == fmap Just (print 1) do (t, _) <- duration $ timeout 0.1 $ sleep 1000; print t; return $ t < 1 timeout 0.1 (sleep 2 >> print 1) == return NothingCalculate the difference between two times in seconds. Usually the first time will be the end of an event, and the second time will be the beginning.nShow a number of seconds, typically a duration, in a suitable manner with responable precision for a human. showDuration 3.435 == "3.44s" showDuration 623.8 == "10m24s" showDuration 62003.8 == "17h13m" showDuration 1e8 == "27777h47m"Call once to start, then call repeatedly to get the elapsed time since the first call. The time is guaranteed to be monotonic. This function is robust to system time changes. Ado f <- offsetTime; xs <- replicateM 10 f; return $ xs == sort xsA synonym for .'Record how long a computation takes in . ;do (a,_) <- duration $ sleep 1; return $ a >= 1 && a <= 1.1 tu tuSafeL=Starts out empty, then is filled exactly once. As an example: bar <-  forkIO $ do ...; val <- ...;  bar val print =<<  bar PHere we create a barrier which will contain some computed value. A thread is forked to fill the barrier, while the main thread waits for it to complete. A barrier has similarities to a future or promise from other languages, has been known as an IVar in other Haskell work, and in some ways is like a manually managed thunk.oLike an MVar, but must always be full. Used to on a mutable variable in a thread-safe way. As an example: hits <-  0 forkIO $ do ...;  hits (+1); ... i <-  hits print (HITS,i) Here we have a variable which we modify atomically, so modifications are not interleaved. This use of MVar never blocks on a put. No modifyVar operation should ever block, and they should always complete in a reasonable timeframe. A Var should not be used to protect some external resource, only the variable contained within. Information from a readVar should not be subsequently inserted back into the Var.Like an MVar, but has no value. Used to guarantees single-threaded access, typically to some system resource. As an example: lock <-  let output = L . putStrLn forkIO $ do ...; output "hello" forkIO $ do ...; output "world" Here we are creating a lock to ensure that when writing output our messages do not get interleaved. This use of MVar never blocks on a put. It is permissible, but rare, that a withLock contains a withLock inside it - but if so, watch out for deadlocks.On GHC 7.6 and above with the  -threaded flag, brackets a call to #. On lower versions (which lack .) this function just runs the argument action.Given an action, produce a wrapped action that runs at most once. If the function raises an exception, the same exception will be reraised each time. let x ||| y = do t1 <- onceFork x; t2 <- onceFork y; t1; t2 \(x :: IO Int) -> void (once x) == return () \(x :: IO Int) -> join (once x) == x \(x :: IO Int) -> (do y <- once x; y; y) == x \(x :: IO Int) -> (do y <- once x; y ||| y) == xLike H, but immediately starts running the computation on a background thread. Z\(x :: IO Int) -> join (onceFork x) == x \(x :: IO Int) -> (do a <- onceFork x; a; a) == x Create a new .%Perform some operation while holding 6. Will prevent all other operations from using the  while the action is ongoing.Like Y but will never block. If the operation cannot be executed immediately it will return %. Create a new  with a value.Read the current value of the . Modify a + producing a new value and a return result. Modify a , a restricted version of ..Perform some operation using the value in the , a restricted version of . Create a new .4Write a value into the Barrier, releasing anyone at +. Any subsequent attempts to signal the  will throw an exception.,Wait until a barrier has been signaled with . A version of  that never blocks, returning %- if the barrier has not yet been signaled.vwxyz{|O}~Avwxyz{|NoneTLike , but setting an encoding.Like , but with the encoding .Like , but for binary files.A strict version of .A strict version of . When the string is produced, the entire file will have been read into memory and the file handle will have been closed. Closing the file handle does not rely on the garbage collector. f\(filter isHexDigit -> s) -> fmap (== s) $ withTempFile $ \file -> do writeFile file s; readFile' fileA strict version of , see  for details.A strict version of , see  for details.A strict version of , see  for details.(Write a file with a particular encoding.Write a file with the  encoding. W\s -> withTempFile $ \file -> do writeFileUTF8 file s; fmap (== s) $ readFileUTF8' fileWrite a binary file. [\s -> withTempFile $ \file -> do writeFileBinary file s; fmap (== s) $ readFileBinary' file Capture the  and  of a computation. ,captureOutput (print 1) == return ("1\n",()) Execute an action with a custom , a wrapper around .nProvide a function to create a temporary file, and a way to delete a temporary file. Most users should use $ which combines these operations.Create a temporary file in the temporary directory. The file will be deleted after the action completes (provided the file is not still open). The  will not have any file extension, will exist, and will be zero bytes long. If you require a file with a specific name, use . withTempFile doesFileExist == return True (doesFileExist =<< withTempFile return) == return False withTempFile readFile' == return ""xProvide a function to create a temporary directory, and a way to delete a temporary directory. Most users should use $ which combines these operations.Create a temporary directory inside the system temporary directory. The directory will be deleted after the action completes. withTempDir doesDirectoryExist == return True (doesDirectoryExist =<< withTempDir return) == return False withTempDir listFiles == return []Returns $ when both files have the same size.Returs - when the contents of both files is the same.Returns S if both files have the same content. Raises an error if either file is missing. fileEq "does_not_exist1" "does_not_exist2" == undefined fileEq "does_not_exist" "does_not_exist" == undefined withTempFile $ \f1 -> fileEq "does_not_exist" f1 == undefined withTempFile $ \f1 -> withTempFile $ \f2 -> fileEq f1 f2 withTempFile $ \f1 -> withTempFile $ \f2 -> writeFile f1 "a" >> writeFile f2 "a" >> fileEq f1 f2 withTempFile $ \f1 -> withTempFile $ \f2 -> writeFile f1 "a" >> writeFile f2 "b" >> notM (fileEq f1 f2){      !"#$NoneL A version of %% that also captures the output, both  and . Returns a pair of the & and the output. A version of % that throws an error if the & is not '. A version of % that captures the output (both  and  ) and throws an error if the & is not '.5(%)*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWX None   !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~|{~ }^_`abhicdefgtujklmnorspq [\]YZ786459:/.0CDN3OPQEFJKLMR*+,-HI=>?SUT<;')(%&G12B@A !"#$  XzvwyxY ! "#$#%#&'()*+,+-./.0121234356789: ; < = > ? @ A B C   D E F G HIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~                    ) )!)"#$%$&$'$($))*)+),)-).)/)0)1)2)3)4)5)6)7)8)9):);)<)=)>)?)@)A)B)C)D)E)F)G)HIJIKILIMINOPQROS6T6U6VWX6Y6Z3[3\]^3_3`3aObWcWdOefghijklmnopOq6r6sWtWuWvWwWxWyWzW{W|W}W~WWWWWWWW33333333333333333333333333333333333333333333333333666666666666666666666666###+++++++QOfffOOOOOOOO W W W W OOOOOOOOOO89898989898989 89!89"89#89$89%89&89'89(89)89*89+89,89-89.89/89089189289389489589689789889989:89;89<89=89>89?89@89A89B89C89D89E89F89G89H89I89J89K89L89M8NOPQR'STU'V'WTXTYTZT[T\]O^_`_a_b_bTcTdTeTfTgThTiTiTjTjTkTkTlTlTmTmTnTnToToTpTp qQrQsQtQuQuQvQvQwQwQxQxQyQyQzQzQ{Q|Q}Q~QQQQ''''S'''''''''W                !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHHIJKLMNMOMPMQRSRTRURVRWXYZQ[Q\XY]XY^XY_XY`XYaXYbXYcXYdXYeXYfXYgXYhXYiXYjXYkXYlXYmXYnXYoXYpXqrXqsXqtXquXvwXvwXvxXvyXvzXv{Xv|Xv}Xv~XvXvXvXvXvXvXvXvXvXvXvXvXvXvXvXv"extra-1.4.11-OzkwpZDRGICRiRi3QLdSCData.Version.ExtraSystem.Environment.ExtraControl.Concurrent.ExtraData.IORef.ExtraControl.Exception.ExtraData.Typeable.ExtraData.Either.ExtraData.List.ExtraExtraSystem.Info.Extra Numeric.ExtraData.Tuple.ExtraControl.Monad.ExtraSystem.Directory.ExtraSystem.Time.ExtraSystem.IO.ExtraSystem.Process.Extra Control.Arrow***&&&System.Timeouttimeoutbase Data.Version makeVersionSystem.Environment lookupEnv!System.Environment.ExecutablePathgetExecutablePathControl.Concurrent forkFinally GHC.Conc.SyncsetNumCapabilitiesgetNumCapabilities Data.IORefatomicWriteIORefatomicModifyIORef' modifyIORef' GHC.ExceptiondisplayExceptionData.Typeable.InternaltypeRep Data.EitherisRightisLeftData.Type.EqualityRefl:~: Data.ProxyProxy Data.OldListsortOn dropWhileEndGHC.Listunconsdirectory-1.2.6.2System.DirectorywithCurrentDirectory isWindowsisMacshowDP intToDouble intToFloat floatToDouble doubleToFloatfirstseconddupebothfst3snd3thd3 repeatedlyfordisjointanySameallSamelistunsnocconssnoctakeEnddropEnd splitAtEnd concatUnzip concatUnzip3 takeWhileEnd trimStarttrimEndtrimlowerupperword1line1groupOnnubOn groupSort groupSortOn groupSortBymergemergeByreplacebreakEndspanEndwordsBylinesBy firstJustdrop1 mconcatMapbreakOn breakOnEndsplitOnsplit dropWhileEnd' stripSuffix stripInfix stripInfixEndchunksOfnubOrdnubOrdOnnubOrdBy $fShowColor$fShowRB readVersion writeIORef'atomicWriteIORef'fromLeft fromRight fromEitherwhenJust whenJustMunitmaybeMeitherM partitionM concatMapM concatForM mconcatMapM mapMaybeMloopMwhileMwhenMunlessMifMnotM||^&&^anyMallMorMandMfindM firstJustM listContents listFileslistFilesRecursivelistFilesInsidecreateDirectoryPrivatestringException showExceptionignoreerrorIOretry retryBoolcatch_ catchJust_handle_ handleJust_try_tryJust_ catchBool handleBooltryBoolSecondssleep subtractTime showDuration offsetTimeoffsetTimeIncreaseduration$fExceptionTimeout $fShowTimeout $fEqTimeoutBarrierVarLockwithNumCapabilitiesonceonceForknewLockwithLock withLockTrynewVarreadVar modifyVar modifyVar_withVar newBarrier signalBarrier waitBarrierwaitBarrierMaybereadFileEncoding readFileUTF8readFileBinary readFile'readFileEncoding' readFileUTF8'readFileBinary'writeFileEncoding writeFileUTF8writeFileBinary captureOutput withBuffering newTempFile withTempFile newTempDir withTempDirfileEq systemOutputsystem_ systemOutput_ghc-prim GHC.TypesTrueFalse System.Info compilerNamearchoscompilerVersiongetEnvironment withProgNamewithArgsunsetEnvsetEnvgetEnv getProgNamegetArgsGHC.Real fromIntegral realToFrac GHC.FloatFloatingpiexplogsqrt**logBasesincostanasinacosatansinhcoshtanhasinhacoshatanhlog1pexpm1log1pexplog1mexpNumericshowOctshowHex showIntAtBase showGFloatAlt showFFloatAlt showGFloat showFFloat showEFloatshowInt readSigned readFloatreadHexreadDecreadOctreadIntGHC.Read lexDigitsfromRat floatToDigits showFloat showSignedmkAppTyTypeableTypeRepTyCon Data.Typeablegcast2gcast1gcasteqTcast rnfTypeRep showsTypeReptypeOf7typeOf6typeOf5typeOf4typeOf3typeOf2typeOf1typeOf typeRepArgs typeRepTyCon funResultTy splitTyConAppmkFunTy mkTyConApptypeRepFingerprintrnfTyConmkTyCon3tyConFingerprint tyConString tyConName tyConModule tyConPackage Typeable1 Typeable2 Typeable3 Typeable4 Typeable5 Typeable6 Typeable7 Data.TuplefstsndswapuncurrycurryGHC.Basemap Data.MaybemaybeNothinginitlastunzip Data.Foldableconcatunzip3 takeWhilegroupnub Data.FunctiononsortwordslinesJustfind concatMapMonoid GHC.ClassesOrdRBETColorRBinsertRBmemberRBbalance++filterzipfoldrnulllengthfoldlfoldl'foldl1sumproductfoldr1maximumminimumelem Data.ListisSubsequenceOfData.Traversable mapAccumR mapAccumLnotElem minimumBy maximumByallanyorandunwordsunlinesunfoldrsortBy permutations subsequencestailsinitsgroupBydeleteFirstsByunzip7unzip6unzip5unzip4zipWith7zipWith6zipWith5zipWith4zip7zip6zip5zip4genericReplicate genericIndexgenericSplitAt genericDrop genericTake genericLengthinsertByinsert partition transpose intercalate intersperse intersectBy intersectunionByunion\\deleteBydeletenubBy isInfixOf isSuffixOf isPrefixOf findIndices findIndex elemIndices elemIndex stripPrefixzipWith3zipWithzip3!!lookupreversebreakspansplitAtdroptake dropWhilecycle replicaterepeatiteratescanr1scanrscanl'scanl1scanlfoldl1'tailheadVersion parseVersion showVersion versionBranch versionTags GHC.IORef writeIORefatomicModifyIORef modifyIORef mkWeakIORef readIORefnewIORefIORefLeftRightEitherpartitionEithersrightsleftseithermapMaybewhen Control.Monadunlessnot||&&guardjoinMonad>>=>>returnfailFunctorfmapmapMsequencemfilter<$!> replicateM_ replicateMfoldM_foldM zipWithM_zipWithM mapAndUnzipMforever<=<>=>filterMforMmsum sequence_forM_mapM_ Data.FunctorvoidapliftM5liftM4liftM3liftM2liftM=<< MonadPlusmzeromplusgetDirectoryContentscreateDirectorygetTemporaryDirectorygetUserDocumentsDirectorygetAppUserDataDirectorygetXdgDirectorygetHomeDirectorysetModificationTime setAccessTimegetModificationTime getAccessTimeisSymbolicLink doesFileExistdoesDirectoryExistsetCurrentDirectorygetCurrentDirectory listDirectory findFilesWith findFileWith findFilesfindFilefindExecutablesInDirectoriesfindExecutablesfindExecutablemakeRelativeToCurrentDirectory makeAbsolutecanonicalizePathcopyFileWithMetadatacopyFile renameFilerenameDirectory removeFileremoveDirectoryRecursiveremoveDirectorycreateDirectoryIfMissingcopyPermissionssetPermissionsgetPermissionssetOwnerSearchablesetOwnerExecutablesetOwnerWritablesetOwnerReadableemptyPermissions Permissionsreadablewritable executable searchable XdgDirectoryXdgData XdgConfigXdgCache System.Directory.Internal.Config exeExtensionIOGHC.IO.Exception IOException ErrorCallControl.Exception.Basecatch Exception SomeException catchJusthandle handleJusttrytryJustboolassertControl.ExceptionallowInterruptcatchesHandlerbracketOnErrorbracket_finallybracket onException mapExceptionPatternMatchFail RecSelError RecConError RecUpdError NoMethodError TypeErrorNonTerminationNestedAtomicallythrowToioErrorasyncExceptionFromExceptionasyncExceptionToExceptionBlockedIndefinitelyOnMVarBlockedIndefinitelyOnSTMDeadlockAllocationLimitExceededAssertionFailedSomeAsyncExceptionAsyncException StackOverflow HeapOverflow ThreadKilled UserInterruptArrayExceptionIndexOutOfBoundsUndefinedElementGHC.IOevaluateuninterruptibleMaskuninterruptibleMask_maskmask_getMaskingState interruptiblethrowIO MaskingStateUnmaskedMaskedInterruptibleMaskedUninterruptiblethrow toException fromExceptionErrorCallWithLocationArithExceptionOverflow UnderflowLossOfPrecision DivideByZeroDenormalRatioZeroDenominatorDoubleIntTimeoutOnce OncePending OnceRunningOnceDonethreadWaitWriteSTMthreadWaitReadSTMthreadWaitWritethreadWaitReadrunInUnboundThreadrunInBoundThreadisCurrentThreadBoundforkOSWithUnmaskforkOSrtsSupportsBoundThreadsControl.Concurrent.QSemN signalQSemN waitQSemNnewQSemNQSemNControl.Concurrent.QSem signalQSemwaitQSemnewQSemQSemControl.Concurrent.ChanwriteList2ChangetChanContents isEmptyChan unGetChandupChanreadChan writeChannewChanChan GHC.Conc.IO threadDelayControl.Concurrent.MVar mkWeakMVaraddMVarFinalizermodifyMVarMaskedmodifyMVarMasked_ modifyMVar modifyMVar_withMVarMaskedwithMVarswapMVarmkWeakThreadIdthreadCapabilityyield myThreadId killThreadforkOnWithUnmaskforkOnforkIOWithUnmaskforkIOThreadIdGHC.MVar isEmptyMVar tryReadMVar tryPutMVar tryTakeMVarputMVarreadMVartakeMVarnewMVar newEmptyMVarMVar System.IOreadFileGHC.IO.Encodingutf8 hGetContents'GHC.IO.Handle.Text hGetContentsGHC.IO.Handle.FDstdoutstderrGHC.IO.Handle.Types BufferMode GHC.IO.Handle hSetBufferingFilePathsameSize sameContentmemcmptempRef tempUniqueprintHandle(openBinaryTempFileWithDefaultPermissions"openTempFileWithDefaultPermissionsopenBinaryTempFile openTempFilefixIOwithBinaryFilewithFilehPrinthReadylocaleEncodingreadIOreadLn appendFile writeFileinteract getContentsgetLinegetCharputStrLnputStrputCharopenBinaryFileopenFileisEOFstdinhShowhSetNewlineModehSetBinaryModehIsTerminalDevicehGetEchohSetEcho hIsSeekable hGetBuffering hIsWritable hIsReadable hIsClosedhIsOpenhTellhSeekhSetPosnhGetPosn hGetEncoding hSetEncoding hLookAheadhIsEOF hSetFileSize hFileSizehClose HandlePosnhGetBufNonBlocking hGetBufSomehGetBufhPutBufNonBlockinghPutBuf hPutStrLnhPutStrhPutCharhGetLinehGetChar hWaitForInputmkTextEncodingchar8utf32beutf32leutf32utf16beutf16leutf16utf8_bomlatin1hFlushnoNewlineTranslationnativeNewlineModeuniversalNewlineMode nativeNewline NoBuffering LineBufferingBlockBufferingNewlineLFCRLF NewlineModeinputNLoutputNLGHC.IO.Encoding.Types TextEncoding GHC.IO.DeviceSeekMode AbsoluteSeek RelativeSeek SeekFromEnd GHC.IO.IOModeIOModeReadMode WriteMode AppendMode ReadWriteModeprocess-1.4.2.0System.ProcesssystemExitCode ExitSuccess rawSystemrunInteractiveProcessrunInteractiveCommand runProcess runCommandterminateProcessgetProcessExitCodewaitForProcessshowCommandForUserreadCreateProcessWithExitCodereadProcessWithExitCodereadCreateProcess readProcess callCommand callProcess spawnCommand spawnProcess createProcessshellprocSystem.Process.InternalsinterruptProcessGroupOf createPipeFd createPipecreateProcess_System.Process.Common CreateProcesscmdspeccwdenvstd_instd_outstd_err close_fds create_group delegate_ctlcdetach_consolecreate_new_console new_session child_group child_userCmdSpec ShellCommand RawCommand StdStreamInherit UseHandle CreatePipeNoStream ProcessHandle